Gas flow and heat transfer in a pancake chemical vapor deposition reactor

Abstract

Gas flow and heat transfer in a pancake reactor for silicon epitaxial film growth are discussed based on a gas flow visualization technique, numerial calculations and a growth rate profile of silicon epitaxial film. In the gas flow visualization, motions of NH 4Cl or SiO 2 particles are observed using a high-sensitivity analogue camera. The observed gas flow motions are compared with those obtained by three-dimensional calculations of the transport equations of the mass, momentum and energy. At room temperature and the epitaxial growth temperature of 1423 K, a large recirculation in the reactor chamber exists. The gas flow direction near the susceptor at the epitaxial growth temperature is nearly the same as that at room temperature, that is, from the outside toward the center of the susceptor. The profile of the epitaxial film growth rate observed agrees qualitatively with that predicted by visualization and calculations. The gas flow motions near the susceptor in the pancake reactor are parallel to the susceptor, in agreement with that of a horizontal reactor.